docs: Use one file to describe dependencies

docs/installation/alpine_linux_en.md

@@ -5,25 +5,7 @@ This guide is a step-by-step installation guide for Alpine Linux. The instructio
 
 It assumes that you have administrative rights, either as root or a user with [sudo permissions](https://www.linode.com/docs/tools-reference/custom-kernels-distros/install-alpine-linux-on-your-linode/#configuration). If you want to run this guide with root, ignore the `sudo` at the beginning of the lines, unless it calls a user like `sudo -Hu pleroma`; in this case, use `su -l <username> -s $SHELL -c 'command'` instead.
 
-### Required packages
+{! backend/installation/generic_dependencies.include !}
-
-* `postgresql`
-* `elixir`
-* `erlang`
-* `erlang-parsetools`
-* `erlang-xmerl`
-* `git`
-* `file-dev`
-* Development Tools
-* `cmake`
-
-#### Optional packages used in this guide
-
-* `nginx` (preferred, example configs for other reverse proxies can be found in the repo)
-* `certbot` (or any other ACME client for Let’s Encrypt certificates)
-* `ImageMagick`
-* `ffmpeg`
-* `exiftool`
 
 ### Prepare the system
 

docs/installation/debian_based_en.md

@@ -3,25 +3,7 @@
 
 This guide will assume you are on Debian Stretch. This guide should also work with Ubuntu 16.04 and 18.04. It also assumes that you have administrative rights, either as root or a user with [sudo permissions](https://www.digitalocean.com/community/tutorials/how-to-add-delete-and-grant-sudo-privileges-to-users-on-a-debian-vps). If you want to run this guide with root, ignore the `sudo` at the beginning of the lines, unless it calls a user like `sudo -Hu pleroma`; in this case, use `su <username> -s $SHELL -c 'command'` instead.
 
-### Required packages
+{! backend/installation/generic_dependencies.include !}
-
-* `postgresql` (9.6+, Ubuntu 16.04 comes with 9.5, you can get a newer version from [here](https://www.postgresql.org/download/linux/ubuntu/))
-* `postgresql-contrib` (9.6+, same situtation as above)
-* `elixir` (1.8+, Follow the guide to install from the Erlang Solutions repo or use [asdf](https://github.com/asdf-vm/asdf) as the pleroma user)
-* `erlang-dev`
-* `erlang-nox`
-* `libmagic-dev`
-* `git`
-* `build-essential`
-* `cmake`
-
-#### Optional packages used in this guide
-
-* `nginx` (preferred, example configs for other reverse proxies can be found in the repo)
-* `certbot` (or any other ACME client for Let’s Encrypt certificates)
-* `ImageMagick`
-* `ffmpeg`
-* `exiftool`
 
 ### Prepare the system
 

docs/installation/freebsd_en.md

@@ -2,7 +2,9 @@
 
 This document was written for FreeBSD 12.1, but should be work on future releases.
 
-## Required software
+{! backend/installation/generic_dependencies.include !}
+
+## Installing software used in this guide
 
 This assumes the target system has `pkg(8)`.
 

docs/installation/generic_dependencies.include

@@ -0,0 +1,16 @@
+## Required dependencies
+
+* PostgreSQL 9.6+
+* Elixir 1.9+
+* Erlang OTP 22.2+
+* git
+* file / libmagic
+* gcc (clang might also work)
+* GNU make
+* CMake
+
+## Optionnal dependencies
+
+* ImageMagick
+* FFmpeg
+* exiftool

docs/installation/gentoo_en.md

@@ -3,9 +3,7 @@
 
 This guide will assume that you have administrative rights, either as root or a user with [sudo permissions](https://wiki.gentoo.org/wiki/Sudo). Lines that begin with `#` indicate that they should be run as the superuser. Lines using `$` should be run as the indicated user, e.g. `pleroma$` should be run as the `pleroma` user.
 
-### Configuring your hostname (optional)
+{! backend/installation/generic_dependencies.include !}
-
-If you would like your prompt to permanently include your host/domain, change `/etc/conf.d/hostname` to your hostname. You can reboot or use the `hostname` command to make immediate changes.
 
 ### Your make.conf, package.use, and USE flags
 

docs/installation/netbsd_en.md

@@ -1,6 +1,8 @@
 # Installing on NetBSD
 
-## Required software
+{! backend/installation/generic_dependencies.include !}
+
+## Installing software used in this guide
 
 pkgin should have been installed by the NetBSD installer if you selected
 the right options. If it isn't installed, install it using pkg_add.

docs/installation/openbsd_en.md

@@ -4,19 +4,11 @@ This guide describes the installation and configuration of pleroma (and the requ
 
 For any additional information regarding commands and configuration files mentioned here, check the man pages [online](https://man.openbsd.org/) or directly on your server with the man command.
 
+{! backend/installation/generic_dependencies.include !}
+
+### Preparing the system
 #### Required software
 
-The following packages need to be installed:
-
-  * elixir
-  * gmake
-  * git
-  * postgresql-server
-  * postgresql-contrib
-  * cmake
-  * ffmpeg
-  * ImageMagick
-
 To install them, run the following command (with doas or as root):
 
 ```